Rivista Italiana di Paleontologia e Stratigrafia (Research in Paleontology and Stratigraphy) vol. 123(2): 211-218. July 2017 NYCTEREUTES MEGAMASTOIDES (CANIDAE, MAMMALIA) FROM THE EARLY AND MIDDLE VILLAFRANCHIAN (LATE PLIOCENE AND EARLY PLEISTOCENE) OF THE LOWER VALDARNO (FIRENZE AND PISA, TUSCANY, ITALY) SAVERIO BARTOLINI LUCENTI1, 2 1 Dottorato di Ricerca in Scienze della Terra, Università di Pisa, Via S. Maria 53, 56126 Pisa, Italy. 2 Dipartimento di Scienze della Terra, Università di Firenze, Via G. La Pira 4, 50121 Firenze, Italy. E-mail: [email protected] To cite this article: Bartolini Lucenti S. (2017) - Nyctereutes megamastoides (Canidae, Mammalia) from the early and middle Villafranchian (Late Pliocene and Early Pleistocene) of the Lower Valdarno (Firenze and Pisa, Tuscany, Italy). Riv. It. Paleontol. Strat., 123(2): 211-218. Keywords: Nyctereutes; canids; Villafranchian; S. Giusto; Montopoli; Italy. Abstract. Among living canids, the genus Nyctereutes Temminck, 1838 was the first to appear in the Western European fossil record. In the Italian Peninsula, scanty remains from a few Plio-Pleistocene localities of central Italy, referable to the Triversa Faunal Unit (FU) and the Montopoli FU, were historically attributed to Nyctereutes megamastoides (Pomel, 1842). Here we describe the partially unpublished Nyctereutes remains from two localities of the Lower Valdarno (Tuscany), S. Giusto (Florence; early Villafranchian) and Montopoli (Pisa; middle Villafranchian), and compare them with both extant and fossil species of this genus. The material described herein most closely resembles the remains from Spain, France and other European sites previously attributed to N. megamastoides in proportions and morphological features, hence confirming the presence of this relatively widespread species in Italy from the Pliocene to the Early Pleistocene. Besides the scanty material, the Lower Valdarno record of N. megamastoides represents one of the earliest of the species in Europe and allows to report, for the first time, the occurrence of a derived form of Nyctereutes in the Late Pliocene of Italy. This early record confirms that the evolu- tionary pattern of Asia, where the advanced N. sinensis is associated with the primitive N. tingi, was different in the Pliocene of Europe. INTRODUCTION by Nyctereutes sp. (see Tedford & Qiu 1991). N. si- nensis in some respects resembles the European ta- The earliest fossil record of the genus Nycte- xon recovered from French and Spanish sites like reutes Temminck, 1838 in Eurasia dates back to the Senèze and Villaroya, Nyctereutes megamastoides (Po- Early Pliocene with the presence of two contem- mel, 1842), which is considered the phyletic descen- porary species: Nyctereutes tingi Tedford & Qiu, 1991 dant of N. donnezani. In their review of the Pliocene in the Yushe Basin, China, and Nyctereutes donneza- Nyctereutes species of Eurasia, Soria & Aguirre (1976) ni (Depéret, 1890) in Western Europe (Ruscinian identified two subspecies ofN. megamastoides: N. me- time, Tedford & Qiu 1991). Other European fin- gamastoides megamastoides from western European si- dings were ascribed to N. tingi, e.g., those of the tes like Perrier-Etouaires, Perrier-Pardines, Senèze Bulgarian site of Varshets (see Spassov 1997; 2003) (France), Chilhac, Villaroya (Spain) and Csárnota and those of Megalo Emvolon (Greece; see Koufos (Hungary); and N. megamastoides vulpinus from St. 1997). Tedford & Qiu (1991) suggested that these Vallier (France), suggesting the possible attribution two species may represent a single taxon with a wide of the material from La Puebla de Valverde (Spain) Paleoartic distribution. to this subspecies. This distinction is based on diffe- In some Chinese localities, together with N. rences in dental proportions (e.g. the elongation of tingi, there is also a more derived species, Nyctereutes the premolars and of the carnassials and the M2 re- sinensis (Schlosser, 1903) (see Tehilhard de Chardin duced length in comparison to N. m. megamastoides). & Pei 1941). This larger and more evolved taxon Recently, Monguillon et al. (2004), revised the abun- was replaced during the Early-Middle Pleistocene dant material of St. Vallier, proposing to raise the subspecies N. m. vulpinus to the rank of species as the Received: November 24, 2016; accepted: February 28, 2017 differences with N. megamastoides (sensu N. m. mega- 212 Bartolini Lucenti S. mastoides of Soria and Aguirre 1976) testify to adap- early Villafranchian Triversa FU and are correlated tations to a more carnivorous diet. The authors con- to the Gauss Chron (Sala & Masini 2007). sidered the hypothesis that N. vulpinus evolved from An unpublished Nyctereutes hemimandible the European population of N. tingi more plausible. fragment from S. Giusto is kept in the collections There is a consistent hiatus in the Eurasian fossil of the Natural History Museum, Geological and Pa- record of Nyctereutes during the Early Pleistocene. leontological section, of the University of Florence Nowadays Nyctereutes procyonoides (Gray, 1834) is the with inventory number IGF 10132. The specimen only living species of its genus. Its geographic di- was recovered during a sampling excavation in 1916 stribution is composed of an original Asian range and later donated to the Museum by Prof. A. Fucini. (Eastern Siberia, Northern China, North Vietnam, Korea and Japan) and a European range (Finland, Montopoli - Montopoli is an important large Sweden, Norway, Poland, Germany, France and mammal fauna site since it is the first middle Villa- Hungary), where they were introduced between franchian (Early Pleistocene) large mammal assem- the 1930s and the 1950s. The earliest record of the blage. Montopoli is stratigraphically superposed on extant N. procyonoides is in Zhoukoudian localities the fauna of the Triversa unit and shallow-water 1 and 13: these fossil specimens differ from the li- marine sediments of Early Pleistocene age (Middle ving individuals only by the larger size (see Tedford Pliocene in papers prior to the IUGS 2009 decision; & Qiu 1991). The phylogenetic relationship of N. cf. Benvenuti et al. 1995). This fauna is celebrated in procyonoides to the other Eurasian forms is still un- the literature for its important signs of environmen- clear, though it is reasonable to consider N. sinensis tal change given by the dispersals of a primitive spe- the closest fossil species to the living raccoon-dog, cies of the genus Mammuthus (Palombo & Ferretti as suggested by Tedford & Qiu (1991). 2005), the monodactyl horse Equus cf. livenzovensis, The Villafranchian (Late Pliocene to Early the large deer Eucladoceros tegulensis, and Gazella bor- Pleistocene) fossil record in Italy records three oc- bonica, as well as the disappearance of some taxa currences of Nyctereutes (Gliozzi et al. 1997; Rook & with subtropical affinities still characterizing the Martinez Navarro 2010). One is from the Collepar- previous early Villafranchian assemblages (Pradella do local fauna (Anagni Basin, Latium; Montopoli & Rook 2007). FU, Gliozzi et al. 1997) two from the Lower Val- The Montopoli Faunal Unit (corresponding darno (Tuscany; Triversa FU and Montopoli FU). to unit MN16b in the European MN sub-division) The latter (two specimens housed in the Museum was originally included in the early Villafranchian of Natural History of the University of Florence) (Azzaroli 1977; Azzaroli et al. 1988), but the marked are the subject of this paper. faunal turnover characterizing the transition from the early Villafranchian Triversa FU to the Mon- topoli FU suggested considering Montopoli as the NYCTEREUTES FROM LOWER VALDARNO basal unit of the middle Villafranchian (Caloi & Pa- lombo 1996; Gliozzi et al. 1997). Montopoli, and the The Lower Valdarno basin has yielded Nycte- related faunal unit, occurs at the Gauss–Matuyama reutes remains from two different localities: San transition (Lindsay et al. 1980) thus correlating with Giusto (Triversa FU, early Villanyian, early Villa- the recently redefined Plio/Pleistocene boundary franchian, Late Pliocene; Florence), and Montopoli (Gelasian Stage, GSSP at Monte san Nicola Section, (Montopoli FU, middle Villafranchian, Early Plei- Sicily; Rio et al. 1994; Gradstein et al. 2004). stocene, Pisa). Del Campana (1913) discussed the attribution of a right maxillary fragment (IGF 10131) from San Giusto - San Giusto is a well-known early Montopoli to Vulpes alopecoides (Major, 1875). The Villanyian (Late Pliocene) locality that yielded the specimen, later relabeled in the Florence Museum type specimen of the vole Mimomys stehlini (Kormos inventory as N. megamastoides, has never been descri- 1931; Masini & Torre 1987). Together with other bed in detail, although the occurrence of the species Italian early Villanyian sites (Cascina Arondelli, Asti, has been reported in faunal lists from Montopoli in Piedmont; Arcille, Grosseto, Tuscany) this fauna is all the general papers dealing with the biochrono- coeval with the large mammal assemblages of the logy of Italian mammalian faunas (e.g. Azzaroli et Nyctereutes megamastoides from Villafranchian of Lower Valdarno (Tuscany, Italy) 213 al. 1982; Caloi & Palombo 1996; Gliozzi et al. 1997; Description Palombo et al. 2002). Cranial fragments – The second and third up- per premolar in the specimen IGF 10131_1 (Fig. 1) are rather bucco-lingually flattened, and lack a distal MATERIALS AND METHODS accessory cusp. They are separated by short diaste- mata. In the P4, the protocone is large and directed The described